Flood warnings issued for B.C. rivers amid heavy rain, melting snow

Vancouver -

The BC River Forecast Centre has issued flood warnings for three rivers in the province's Southern Interior as an atmospheric river continues to bring heavy rain to much of B.C. 

The Coquihalla, Tulameen and Coldwater rivers have all "risen rapidly" on Sunday, according to the forecast centre.

Flows on the Tulameen and Coldwater rivers have been observed at "between a 20-year and 50-year return period" at some monitoring stations, the centre said.

On the Coquihalla River, the volume has reached approximately a 10-year flow.

"Temperatures have been rising, with temperatures in the 5 to 7C range being observed at automated snow weather stations across the region," the centre said in its statement.

"Snowmelt is being observed at mid-elevations and is expected to add additional runoff to rivers."

Flood watches were already in place for the Fraser River and its tributaries in the Fraser Valley and Fraser Canyon regions, as well as for the Chilliwack River in the Fraser Valley and the Englishman River on Vancouver Island.

Flood watches are issued when "river levels are rising and will approach or may exceed bankfull," and flood warnings are issued when levels "have exceeded bankfull" or will do so "imminently." 

"The public is advised to stay clear of the fast-flowing rivers and potentially unstable riverbanks during the high-streamflow period," the forecast centre said.

The centre said rivers are expected to continue rising through Sunday as a result of the continued rainfall, before easing on Monday as the heaviest rain passes.

Much of the Lower Mainland and the Southern Interior is under rainfall warnings Sunday. By the time the storm ends on Monday, rainfall totals are expected to range from 100 to 150 millimetres across different parts of the Fraser Valley, according to Environment Canada. 

However, as the rain dissipates, the wind could pick up across the South Coast.

"We have winds coming down both the Juan de Fuca Strait and the Strait of Georgia," said Philippe-Alain Bergeron, an Environment Canada meteorologist. "We’ve got westerly winds anywhere from 40 to 60 kilometres an hour for (Monday) afternoon."